Explore topic-wise MCQs in Chemistry.

This section includes 47 Mcqs, each offering curated multiple-choice questions to sharpen your Chemistry knowledge and support exam preparation. Choose a topic below to get started.

1.

Which one of the following is used as a moderator in the nuclear reactor ?

A. Thorium
B. Graphite
C. Radium
D. Ordinary water
Answer» C. Radium
2.

A gas which burns with blue flame is ?

A. CO
B. O
C. N
D. CO
Answer» E.
3.

For the process CO2 (s) CO2 (g)

A. Both H and S are positive
B. H is negative and S is positive
C. H is positive and S is negative
D. Both H and S are negative
Answer» B. H is negative and S is positive
4.

The molar heat capacity of water is

A. 4.184 JK
B. 75.3 JK
C. 185 JK
D. 1 JK
Answer» C. 185 JK
5.

Vibrational energy can be said as

A. only potential
B. only kinetic
C. (a) & (b) both partially
D. None of these
Answer» D. None of these
6.

The law of Lavoisier and Laplace illustrates

A. The principle of conservation
B. Equivalence of mechanical and thermal energy
C. The principle of conservation of matter
D. Equivalence of mechanical and chemical energy
Answer» B. Equivalence of mechanical and thermal energy
7.

A mixture of carbon monoxide and nitrogen is called

A. Natural gas
B. Water gas
C. Producer gas
D. None
Answer» D. None
8.

During isothermal expansion of an ideal gas, its

A. Internal energy increases
B. Enthalpy decreases
C. Enthalpy remains unaffected
D. Enthalpy reduces to zero
Answer» D. Enthalpy reduces to zero
9.

For an endothermic reaction to be spontaneous

A. S must be positive
B. S must be negative
C. S must be zero
D. G must be positive
Answer» B. S must be negative
10.

An ideal fuel should have

A. High calorific value
B. Low ignition temperature
C. Regulated and controlled
D. All of the above
Answer» E.
11.

For the process CO

A. Both H and S are positive
B. H is negative and S is positive
C. H is positive and S is negative
D. Both H and S are negative
Answer» B. H is negative and S is positive
12.

A mixture of carbon monoxide and hydrogen is called

A. Producer gas
B. Water gas
C. Natural gas
D. None
Answer» C. Natural gas
13.

In which of the following, the entropy decreases ?

A. Crystallisation of sucrose from solution
B. Rusting of iron
C. Melting of ice
D. Vaporization of comphor
Answer» B. Rusting of iron
14.

Which law of thermodynamics introduces the concept of entropy ?

A. First law
B. Zeroth law
C. Third law
D. Second law
Answer» E.
15.

For which one of the following elements, the standard enthalpy is not zero ?

A. C (Diamond)
B. C (Graphic)
C. Liquid mercury
D. Rhombic sulpur
Answer» B. C (Graphic)
16.

In which type of coal percentage of carbon is the highest ?

A. Peat
B. Lignite
C. Bituminous
D. Anthracite
Answer» E.
17.

When ice melts into water, which type of change occurs in entropy ?

A. increases
B. decreases
C. becomes zero
D. remains unchanged
Answer» B. decreases
18.

Which one of the following has maximum colorific value ?

A. Water gas
B. Producer gas
C. Oil gas
D. Coal gas
Answer» D. Coal gas
19.

The ratio of for inert gases is

A. 1.33
B. 1.66
C. 2.13
D. 1.99
Answer» C. 2.13
20.

When ammonium chloride is dissolved in water, the solution becomes cold. The change is

A. Endothermic
B. Exothermic
C. Supercooling
D. None of these
Answer» B. Exothermic
21.

Entropy change of a system and its surroundings in equilibrium

A. Increases
B. Decreases
C. Remains constant
D. Either increases of decreases
Answer» D. Either increases of decreases
22.

The compound with negative heat of formation is known as

A. Endothermic conpound
B. Exothermic compound
C. Ecdoergonic compound
D. None of the above
Answer» C. Ecdoergonic compound
23.

According to latests sign conventions, the correct expression representing the first law of thermodynamics

A. U = q + w
B. U = H + pV
C. U = q - w
D. All the ecpressions are correct
Answer» B. U = H + pV
24.

If system A is in thermal equilibrium with B and B is in thermal equilibrium with C, then A and C are in equilibrium with each other. "This is a statement of

A. Cyclic rute
B. Zeroth law of thermodynamics
C. First law of thermodynamics
D. Second law of thermodynamics
Answer» C. First law of thermodynamics
25.

A substance that can supply energy either along or by reacting with another substance is known as

A. Rayon
B. Fibres
C. Fuels
D. Thiokol
Answer» D. Thiokol
26.

Octane number of fuel can be increased by

A. Isomerisaiton
B. Alkylation
C. Reforming
D. All of these
Answer» E.
27.

Which among the following is an extensive property of the system

A. Temperature
B. Volume
C. Refractive index
D. Viscosity
Answer» C. Refractive index
28.

A gas expands isothermally and reversible. The work done by the gas is

A. Zero
B. Maximum
C. Minimum
D. Cannot be determined
Answer» C. Minimum
29.

During isothermal expansion of an ideal gas, its internal energy

A. decreases
B. increases
C. may increase or decrease
D. remains unchanged
Answer» E.
30.

Which of the following is a closed system ?

A. Jet engine
B. Tea placed in steel kettle
C. Pressure cooker
D. Rocket engine during propulsion
Answer» C. Pressure cooker
31.

The information not conveyed by thermodynamics is about

A. spontaneity of a reaction
B. yields of the products formed
C. rates of reactions
D. all the three above
Answer» D. all the three above
32.

The standard heat of formation of diamond is

A. Same as that of graphite
B. Greater than of graphite
C. Less than that of graphite
D. taken as zero
Answer» C. Less than that of graphite
33.

The calorific value of fat is

A. less than that of carbohydrates and protein
B. less than that of protein but more than carbohydrates
C. less than that of carbohydrate but more than that of protein
D. more than that of carbohydrate and protein
Answer» E.
34.

What happens when the door of a refrigerator is kept open ?

A. Room cooled
B. Room heated
C. Room chilled
D. None of these
Answer» C. Room chilled
35.

Born-Haber cycle is used to determine

A. Electronegativity
B. Lattice energy
C. Both
D. None
Answer» C. Both
36.

The second law of thermodynamics introduced the concept of

A. Electrical energy
B. Entropy
C. Thermal energy
D. None of these
Answer» C. Thermal energy
37.

In any natural process

A. The entropy of universe remains constant
B. The entropy of universe tends towards maximum
C. The entropy of universe towards minimum
D. Any of the above can happen
Answer» C. The entropy of universe towards minimum
38.

If a refrigerator's door is kept open, then

A. room will be cooled
B. room will be heated
C. may get cooled or heated depending upon the weather
D. no effect on room
Answer» C. may get cooled or heated depending upon the weather
39.

A system which can exchange energy with the surrondings but no matter is called

A. a heterogeneous system
B. an open system
C. a closed system
D. an isolated system
Answer» D. an isolated system
40.

Which has maximum calorific value ?

A. Fat
B. Protein
C. Carbohydrate
D. Amino acid
Answer» B. Protein
41.

Which fuel has the maximum calorific value ?

A. Charcoal
B. Kerosene
C. Wood
D. Cow-dung
Answer» C. Wood
42.

The standard state in chemical energetics implies

A. 1 atm pressure at 273 K
B. 1 atm pressure at 297 K
C. 1 bar pressure at 298 K
D. 1 bar pressure at specified temperature
Answer» E.
43.

An intensive property in thermodynamics means a property which depends

A. on the amount of the substance only
B. on the nature of the substance only
C. both on the amount as well as nature of the substance
D. neither on the amount nor on the nature
Answer» C. both on the amount as well as nature of the substance
44.

The order of apperance of the following with increasing temperature during the refining of crude oil is

A. Kerosene, gasoline, diesel
B. Diesel, kerosene, diesel
C. Gasoline, kerosene, diesel
D. Gasoline, diesel, kerosene
Answer» D. Gasoline, diesel, kerosene
45.

The efficiency of a heat engine is maximum when

A. temperature of source is greater than that of sink
B. temperature of sink is greater than that of source
C. temperature difference of source and sink is minimum
D. temperature difference of source and sink is maximum
Answer» E.
46.

During the evaporation of a liquid

A. the enthalpy decreases
B. the enthalpy increases
C. the enthalpy remains unchanged
D. the internal energy decreases
Answer» C. the enthalpy remains unchanged
47.

Which one of the following is used as a

A. Thorium
B. Graphite
C. Radium
D. Ordinary water
Answer» C. Radium